Method and apparatus for processing municipal sludge waste

ABSTRACT

A process for the comminution and dehydration of municipal sludge waste by feeding the municipal sludge waste into a cyclonic, dehydrating comminuter facilitates the further processing of the comminuted and dehydrated sludge material discharged from the comminuter. Both the comminuted and dehydrated sludge material and the air flow discharged from the cyclonic comminuter are sterilized to remove pathogens therefrom. The rate at which the municipal sludge material is fed into the cyclonic comminuter is directly related to the moisture content of the comminuted and dehydrated material discharged from the material discharge opening of the comminuter. Preferably, the moisture content of the discharged material is in the range of 25% to 35% to facilitate the sterilization of the discharged material. An alternative process can be used, however, to dry the discharged comminuted and dehydrated municipal sludge waste material to about 10%, such as by passing the material discharged from the first cyclonic dehydrating comminuter into a second cyclonic dehydrating comminuter until the finally discharged material has a powdery consistency.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 09/338,147, filed Jun. 23, 1999, which claims domestic priorityon U.S. Provisional Patent Application Serial No. 60/090,494, filed onJun. 24, 1998.

BACKGROUND OF THE INVENTION

This invention relates generally to the comminution and dehydration ofmunicipal sludge utilizing a cyclonic comminuter and, more particularly,to the process of treating municipal sewage sludge and relatedmaterials, as a pretreatment conditioner for further appropriatetreatment of the output material.

An environmentally acceptable treatment of municipal sewage sludge hasbecome an important issue. The disposal of municipal sludge with a highpercentage of moisture can be accomplished by composting, but thetransport of the material to the composting site involves thetransportation of 30%-40% moisture, which increases the overall cost ofdisposing of the municipal sludge material. Accordingly, a process,method and apparatus for pre-treating municipal sludge material tocreate an output that is acceptable for further processing treatment ina cost effective way would be highly desirable. Such a process, however,must also be effective in the removal of pathogens from the wasteproduct being treated.

SUMMARY OF THE INVENTION

It is an object of this invention to provide a method of processingmunicipal waste to effect a comminution and a dehydration thereof byfeeding said sludge material into a cyclonic comminuter.

It is another object of this invention to provide a method of processingmunicipal sludge waste including the steps of feeding the sludge intothe air flow of a cyclonic dehumidifying comminuter to comminute thesludge and to effect dehydration thereof, the comminuted and dehydratedsludge being discharged through a material discharge opening at a bottomportion of the cyclonic comminuter while moisture laden air flow isdischarged through an air discharge opening;

sterilizing the discharged air flow after being exhausted from saidcomminuter to remove pathogens therefrom before being released to theatmosphere; and

passing the comminuted and dehydrated sludge material through asterilization chamber after being discharged from the cycloniccomminuter to destroy pathogens therein.

It is a feature of this invention that the flow rate of the municipalsludge through the cyclonic comminuter can be controlled to establish adesired moisture content of the comminuted and dehydrated sludge beingdischarged from the cyclonic comminuter.

It is an advantage of this invention that the comminuted and dehydratedmunicipal sludge being discharged from the cyclonic comminuter can befurther processed by pelletizing or by further drying into a powder forshipment thereof to a remote location, after sterilization.

It is another feature of this invention that an auger can be used formetering the flow of municipal sludge into the infeed of the cycloniccomminuter.

It is another advantage of this invention that the auger used formetering the flow of the sludge waste into the infeed of the cycloniccomminuter will mix different supplies of waste materials containingdifferent moisture levels for feeding into the cyclonic comminuter.

It is still another feature of this invention that the comminuted anddehydrated sludge and the moisture laden air flow discharged from thecyclonic comminuter are sterilized to remove pathogens therefrom.

These and other objects, features, and advantages are accomplishedaccording to the instant invention by providing a process for thecomminution and dehydration of municipal sludge waste by feeding themunicipal sludge waste into a cyclonic, dehydrating comminuter tofacilitate the further processing of the comminuted and dehydratedsludge material discharged from the comminuter. Both the comminuted anddehydrated sludge material and the air flow discharged from the cycloniccomminuter are sterilized to remove pathogens therefrom. The rate atwhich the municipal sludge material is fed into the cyclonic comminuteris directly related to the moisture content of the comminuted anddehydrated material discharged from the material discharge opening ofthe comminuter. Preferably, the moisture content of the dischargedmaterial is in the range of 25% to 35% to facilitate the sterilizationof the discharged material. An alternative process can be used, however,to dry the discharged comminuted and dehydrated municipal sludge wastematerial to about 10%, such as by passing the material discharged fromthe first cyclonic dehydrating comminuter into a second cyclonicdehydrating comminuter until the finally discharged material has apowdery consistency.

BRIEF DESCRIPTION OF THE DRAWINGS

The advantages of this invention will be apparent upon consideration ofthe following detailed disclosure of the invention, especially whentaken in conjunction with the accompanying drawings wherein:

FIG. 1 is a perspective view of a comminuting/dehydrating machineincorporating the principles of the instant invention;

FIG. 2 is a schematic top plan view of the damper mechanism controllingthe flow of air being discharged from the sleeve;

FIG. 3 is a schematic side elevational view of the damper shown in FIG.2;

FIG. 4 is a perspective view of the comminuting/dehydrating machineshown in FIG. 1, but with a sterilizing apparatus positioned to receivematerial discharged from the conical housing;

FIG. 5 is a perspective view of a rasp bar to depict the configurationof each of the plurality of rasp bars lining the interior of theperiphery of the cylindrical portion of the housing;

FIG. 6 is a schematic cross-sectional view of the upper portion of theair discharge sleeve to depict an alternative air flow controlmechanism, one of the vanes being schematically depicted in the centerof the sleeve, the remaining vanes have not been shown for purposes ofclarity;

FIG. 7 is a top plan view of the air discharge sleeve with the air flowcontrol mechanism in a filly closed position;

FIG. 8 is a side elevational view of one of the adjustable vanes; and

FIG. 9 is a end view of one of the adjustable vanes.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Comminuting dense material through a cyclonic comminuting/dehydratingmachine, such as shown in U.S. Pat. No. 3,794,251, issued on Feb. 26,1974, for a “Material Reducing System and Apparatus”, is well known inthe art. A cyclonic comminuting/dehydrating machine similar to thatdisclosed in U.S. Pat. No. 5,236,132, is schematically depicted in theperspective views of FIGS. 1 and 4. The descriptive portions of theaforementioned U.S. Pat. No. 3,794,251 and U.S. Pat. No. 5,236,132 areincorporated herein by reference, particularly with respect to themanner and mechanism through which a cyclonic comminuting/dehydratingmachine operates.

Such a cyclonic comminuting/dehydrating machine 10 operates to create ahigh velocity stream of air from a fan 11 that is directed through aconduit 12 into an inverted conical housing 15. The stream of air isdirected into a tornado-like swirling motion within the housing 15before being discharged out the exit opening 16 at the top centerportion of the housing 15. A damper 20 controls the flow of air throughthe air exit opening 16 and the depth of the swirling motion of the airwithin the housing 15. Preferably, the fan 11 is driven by a powersource, such as an electric motor 11 a that is drivingly connected withthe fan 11 via conventional drive transfer devices (not shown), such asbelts and pulleys. Because of the noise generated by the operation ofthe large fan 11, a silencer 11 b is used to dampen the noise.

A cylindrical sleeve 18, co-operable with the damper 20, is axiallymovable within the housing 15 to also control the depth of cycloniccomminution of material within the housing 15. A pair of linearactuators (not shown), which can be powered hydraulically, pneumaticallyor electrically, can interconnect the sleeve 18 and the sleeve support19 forming the top wall of the cylindrical portion 17 of the housing 15to power the movement of the sleeve 18 within the housing 15. Thepositioning of the sleeve 18 deep into the housing 15 provides forgreater comminution of the material fed through the conduit 12, while ashallow penetration of the sleeve 18 into the housing allows for a morerapid exit of the swirling air from the housing 15 through the air exitopening 16 and, therefore, provides only minimal comminution of thematerial. For a material such as municipal sludge, the cylindricalsleeve 18 will be left in one position. In fact, adjustability of thesleeve 18 would not be desirable for the processing of such a materialand the manufacture of the machine 10 would preferably include a fixedsleeve 18, as opposed to a more versatile, generic machine in which thesleeve 18 would be positionally adjustable.

A discharged air recovery mechanism (not shown) can be provided tocapture the discharged stream of air from the air exit opening 16 toprevent the discharge of any fractional components within the dischargedair into the atmosphere to control pollution and allow the recovery ofany fractional component therein, as will be discussed in greater detailbelow. A material infeed hopper 13 meters the flow of material into theair stream in the conduit 12 so that the material to be comminutedenters the housing 15 generally tangentially with the stream of air fromthe conduit 12. Preferably, the infeed hopper 13 includes an air lock 13a having a rotational member that limits the escape of air from theconduit 12 while feeding material into the conduit 12 for flow into thehousing 15.

The housing 15 includes a cylindrical portion 17 that receives the airstream, and material flowing therein, from the conduit 12 and directsthe air stream into a swirling motion within the housing 15. Dependingimmediately below the cylindrical portion 17 is a conical portion 17 athat directs the swirling air flow into decreasing-radius turns untilthe air can escape up through the sleeve 18, past the damper 20 and intothe discharged air recovery mechanism (not shown). The conical portion 17 a terminates in a material discharge opening 14 at its lowermostextremity for the discharge of comminuted material from the housing 15.

The cylindrical portion 17 is lined with steel rasp bars 17 b (FIG. 5),which may be hardened, and when coupled with the differential forcesassociated with the tornado-like swirling motion of the air streamwithin the housing 15, serve to comminute material fed therein throughimplosion, impaction and centrifugal force, on the basis of quantity anddensity of the material fed therein. At least the upper areas of theconical portion 17 a preferably also have spirally arranged members (notshown) that assist in the comminution of material within the housing 15and deflect material upwardly toward the cylindrical portion 17 tofurther the comminuting process.

As best seen in FIGS. 1-4, the damper 20 is mounted on top of thecylindrical sleeve 18 to control the flow of air dischargedtherethrough. The damper 20 is formed of a generally flat top plate 21welded to a cylindrical skirt 23 to form a cap on the end of the sleeve18. A second flat plate 25 is rotatably supported beneath the top plate21, such as by a pivot bolt 29. Both the top plate and the second plateare formed with openings 22, 26, respectively, arranged adjacent theouter periphery of the plates 21, 25. These openings 22, 26 arealignable upon rotation of the second plate 25 relative to the top plate21 to define a variable sized discharge openings through the damper 20.The relative rotated position of the second plate 25 with respect to thetop plate 21 defines the size of the discharge openings extendingthrough the damper 20 for the discharge of air therethrough. When theopenings 22, 26 are completely aligned, the maximum sized dischargeopening through the damper 20 is obtained.

A fixed cone 27 is positioned below the second plate 25 to directoutwardly the flow of swirling air moving upwardly through the sleeve18, so that the air flow is directed smoothly toward the at leastpartially aligned openings 22, 26. The fixed cone 27 is not adjustable,except that it is preferably affixed to the underside of the secondplate 25 to be rotatable therewith. An actuation handle 28 is affixed tothe second plate 25, preferably through the pivot bolt 29, and extendsoutwardly beyond the boundaries of the sleeve 18 to permit the rotationof the second plate 25 to adjust the size of the openings extendingthrough the damper 20.

One skilled in the art will readily recognize that a powered mechanism(not shown) could be operatively associated with the handle 28 to permitthe remote control of the rotation of the second plate 25 relative tothe top plate 21. Such a powered mechanism (not shown) could include ahydraulic, pneumatic or electric linear actuator, such as an extensiblecylinder, or screw threads interconnecting the handle and either a framereference or the skirt 23 or sleeve 18. Alternatively, a gear, electricor hydraulic motor could also be used to rotate the valve around itscenter pivot shaft.

Referring now to FIGS. 6-9, an alternative (and preferred) embodiment ofthe air flow control mechanism 30 can best be seen. The air flow controlmechanism 30 includes a fixed cone 31 supported in the center of the airdischarge sleeve 18 by a fixed support 32 to force the flow of air beingdischarged up the sleeve 18 into a circular pattern toward the outsideof the sleeve 18. The cone 31 pivotally supports a plurality of vanes 35arranged in an overlapping configuration. Each vane 35 includes a pivotsupport arm 36 that engages the cone 31 and permits movement in a mannerdescribed in greater detail below. The pivot support arm 36 may requirean additional bend to retain the engagement thereof with the cone 31during movement. The body portion 37 of each vane 35 is curved, as bestseen in FIG. 9, and is oriented on top of the adjacent vane 35 on oneside and beneath the adjacent vane 35 on the opposing side to effectsimultaneous movement of the vanes 35 as described below.

The air flow control assembly 30 includes an actuator mechanism 40connected to a first actuator vane 38 on one side of the sleeve 18 andto a second actuator vane 39 on the opposing side of the sleeve 18. Thefirst actuator vane 38 is attached to a first actuator nut 41 havingleft hand threads, while the second actuator vane 39 is attached to asecond actuator nut 43 having right hand threads. A crank arm assembly45, formed of two rods 46, 47 interconnected by a connector coupling 48,is rotatably supported on the sleeve 18 and threadably mounts the twoactuator nuts 41, 43 so that upon rotation of the crank arm assembly 45the two nuts 41, 43 are translated along the length of the rod 46, 47 onwhich they are mounted toward or away from each other, depending on thedirection of rotation of the crank arm assembly 45.

To force the actuator nuts 41, 43 to translate along the correspondingrods 46, 47 upon rotation of the crank arm assembly 45 and to effectmovement of the vanes 35, the actuator nuts 41, 43 are connected to thecorresponding actuator vane 38, 39 by a pin 49 mounted through a pair ofmounting ears (not shown). The mounting ears (not shown) could be formedon either the actuator nut 41, 43 or on each of the respective actuatorvanes 38, 39. The ears (not shown) are formed with slots (not shown) sothat the pins 49 can slide within the corresponding slot (not shown) asthe actuator nuts 41, 43 effect pivotal movement of the actuator vanes38, 39.

In operation, the size of the discharge opening through the sleeve 18 iscontrolled by the rotation of the crank arm assembly 45. By rotating thecrank handle 45 a in a clockwise direction, the left hand threadactuator nut 41 and the right hand thread actuator nut 43, each of whichare connected to the corresponding actuator vane 38, 39 as describedabove, move along the rod 46, 47 toward each other. This motion pullsthe corresponding actuator vanes 38, 39 along with the actuator nuts 41,43, causing the actuator vanes 38, 39 to pivotally move about theirrespective connection with the fixed cone 31 in a generally verticaldirection, creating a gap between the vanes 38, 39 and the circumferenceof the sleeve 18. Since all of the other vanes 35 are overlapped witheach other and with the actuator vanes 38, 39, the generally verticalmovement of the actuator vanes 38, 39 is transferred to the other vanes35, creating an annular ring opening between the vanes 35, 38 and 39 andthe circumference of the sleeve 18.

An opposite rotation of the crank handle 45 a will cause a movement ofthe actuator nuts 41, 43 away from each other. This motion has theopposite effect to that described above, causing the actuator vanes topivotally move downwardly toward the outer circumference of the sleeve18. Again, since the vanes 35, 38 and 39 are arranged in an overlappingconfiguration, all of the vanes 35, 38 and 39 move downwardly together,narrowing the annular gap between the vanes and the sleeve 18 throughwhich the air is discharged.

As with the damper mechanism 20, a powered mechanism (not shown) couldbe operatively associated with the crank handle assembly 45 to permitthe remote control of the rotation thereof to move the vanes 35 up anddown and vary the effective size of the air discharge opening. Such apowered mechanism (not shown) could include a hydraulic, pneumatic orelectric motor that can effect an appropriate rotation of the crank armassembly 45, although the crank handle 45 a would likely need to beremoved.

The operation of the actuators (not shown) controlling the depth ofpenetration of the sleeve 18 within the housing 15 in conjunction withthe operation of the actuator controlling the rotation of the secondplate 25, which can be accomplished either together or separately,controls the flow of air through the comminuting/dehydrating machine 10and, therefore, extent of both the comminution of the material fed intothe housing 15 and the dehydration thereof. The size of the dischargeopenings through the damper 20, which is defined by the extent ofalignment of the openings 22, 26, can be set to a specific percentage ofthe maximum size discharge opening to provide the amount of air flowdesired or the rotated position of the second plate 25 can be programmedto correspond to a specific material being fed into the housing 15 forcomminution and dehydration.

The comminuter/dehydrating machine 10 partially works on the density ofthe material being fed into the air flow through the conduit 12 into thehousing 15, the velocity of the flow of air through the conduit 12 intothe housing 15, and the amount of vacuum found at the discharge opening14 of the conical portion 17 a. All of these factors work together tohold the material in the housing long enough to get the desired results,expressed in terms of the fineness of comminution and the moisturecontent of the material.

Other factors in the operation of the machine 10 include the toughness,hardness, and size, and in some cases, the fibrous content of thematerial being treated. The control of all of these factors can beachieved by controlling two variables, controlling the flow of air andcontrolling the time the material is being processed in the housing 15.The control of the depth of sleeve 18 into the housing 15 and the airflow through the sleeve 18 controls these two variables.

Surprisingly, a cyclonic, dehumidifying comminuting machine 10 has beenfound to be operable to disintegrate considerably less dense materialsuch as municipal sludge. By controlling the level of comminution withinthe housing 15 through manipulating the depth of the sleeve 18 into thehousing 15 and the operation of the damper 20, the amount of comminutionof the sludge material can be selectively controlled. This control notonly permits the extent of comminution of the sludge being fed into thehousing 15, but also the extent of dehydration of the sludge material.Moisture content of the treated product discharged from the comminuter10 is an important factor in the further treatment thereof by furtherappropriate apparatus.

Referring first to FIG. 1, the apparatus for treating municipal sludgecan best be seen. The comminuter/dehydration machine 10 can bepositioned to receive the sludge material from a collection facility(not shown) via a conveyor mechanism (not shown), preferably an augerapparatus. The use of an auger conveyor provides the benefits of servingas a metering device to the material infeed hopper 13 and of preferablymixing the sludge so that a homogeneous, uniform material, at least interms of moisture content, to be processed in the machine 10. This, inturn, allows the operation of the machine to be more consistent toprovide a generally uniform moisture content for the material dischargedfrom the machine 10.

One possible further treatment of the material discharged from themachine 10 is to pelletize the discharged material for shipment to aremote location. A pelletizer works most efficiently at about a 25%-35%(optimally approximately 30%) moisture content. Providing a dischargedmaterial that has a substantially lower moisture content requires thepelletizer to add moisture, usually via the application of steam to thematerial. Infeeding only high moisture sludge to the machine 10 requiresa longer retention time of the material within the housing 15, andthereby reducing throughput; however, some sterilization techniques,such as the utilization of microwaves, is enhanced by moisture in theproduct being sterilized. If such sterilization techniques are used thenthe preferred treatment of the municipal sludge would result in anoutput moisture content of about 30%. In the alternative, however,another possible further treatment that will be recognized by oneskilled in the art includes the removal of moisture down to about 10% orbelow, which would be a powdery consistency, to permit proper storage ortransport to another location for further treatment without pelletizing.

The machine 10 works at ambient temperatures, except for the increase inoperating temperature relating to friction from the fan and the changesin direction from impact with the internal rasp bars 17 b mounted on theinterior periphery of the cylindrical portion 17 of the housing 15. Themoisture in the material being fed into the housing 15 through theconduit 12 is atomized as the material is being comminuted within thehousing 15. The tremendous volume of air flow generated by the fan 11carries this atomized moisture into the sleeve 18 to be discharged fromthe machine 10, thereby dehydrating the material being comminuted. Therate at which the material is fed into the housing 15 is a factor thatdetermines the dryness of the discharged material, as well as the volumeof the material being discharged. If a lower moisture content is desiredin the discharged material, the feed rate of material fed into thehousing 15, such as can be controlled by the auger conveyor mechanismdescribed above, must be slowed.

It has been found that most of the pathogens found in the municipalsludge fed into the housing 15 are discharged with the air flow throughthe sleeve 18, requiring that the discharged air be captured by acollector system for further treatment before being discharged into theatmosphere. Sterilization of the discharged air can be accomplishedaccording to the methods described in greater detail below, includingmicrowaves, plasma arc, ultra-violet light, steam heating and anelectrical discharge mechanism. Surprisingly, tests have shown that incomminuted and dehydrated sludge material, discharged through thematerial discharge opening 14 at a moisture content between 25%-30%, thecontent of pathogens is very low. However, if such material is going tobe pelletized for shipment to a remote location, or subjected to otheradditional processing steps, no pathogens are permitted in thisdischarged material.

Accordingly, the comminuted and dehydrated material being dischargedthrough the opening 14 is collected in a sterilization container 50 thatis cooperatively associated with a conveyor system (not shown) for thepurpose of conveying the discharged material away from the machine 10.Such a conveyor can be of any known type, such as a belt or chainconveyor, an auger or an air delivery system. Prior to being conveyedfrom the sterilization container 50, the discharged material issubjected to a sterilization procedure represented by the microwaveelectron tube 52 or an electric discharge mechanism (not shown) thatcharges a conductor grid. Such an electric discharge mechanism (notshown) creates an electrical arc between grid points which heats thedischarged material to a sufficiently high temperature to kill all ofthe remaining pathogens.

One skilled in the art will readily recognize that other methods ofsterilizing the discharged material can also be used, including the useof a plasma arc, ultra-violet light, steam heating. The sterilizationshould preferably occur immediately after the material is dischargedfrom the opening 14 into the sterilization container 50 as no additionalstep would be necessary in the further processing of the dischargedmaterial, such as pelletizing, unless desired.

It will be understood that changes in the details, materials, steps andarrangements of parts which have been described and illustrated toexplain the nature of the invention will occur to and may be made bythose skilled in the art upon a reading of this disclosure within theprinciples and scope of the invention. The foregoing descriptionillustrates the preferred embodiment of the invention; however,concepts, as based upon the description, may be employed in otherembodiments without departing from the scope of the invention.Accordingly, the following claims are intended to protect the inventionbroadly as well as in the specific form shown.

Having thus described the invention, what is claimed is:
 1. A method ofprocessing sewage sludge, comprising the steps of: feeding said sewagesludge into an air flow of a cyclonic dehumidifying comminuter tocomminute said sewage sludge and to effect dehydration thereof, thecomminuted and dehydrated sewage sludge being discharged through amaterial discharge opening at a bottom portion of said cycloniccomminuter while moisture laden air flow is discharged through an airdischarge opening; metering the flow of said sewage sludge into saidcyclonic comminuter as a function of the moisture level of said sewagesludge; sterilizing said discharged air flow after being exhausted fromsaid comminuter to remove pathogens therefrom before being released tothe atmosphere; passing said comminuted and dehydrated sewage sludgethrough a sterilization apparatus after being discharged from saidcyclonic comminuter to destroy pathogens therein; and further processingsaid sterilized sewage sludge for shipment to a remote location.
 2. Themethod of claim 1 wherein said step of further processing saidsterilized sewage sludge includes the step of: pelletizing saidsterilized sewage sludge.
 3. The method of claim 2 wherein said meteringstep produces a moisture content of said comminuted and dehydratedsewage sludge being discharged from said material discharge opening inthe range of 25% to 35%.
 4. The method of claim 3 wherein said meteringstep includes the step of: using an auger to convey said sewage sludgeto an infeed opening in said cyclonic comminuter.
 5. The method of claim4 wherein said auger mixes sewage sludge containing different levels ofmoisture before metering the mixed sewage sludge into said infeedopening.
 6. The method of claim 3 further comprising the step of:feeding said comminuted and dehydrated sewage sludge into an air flow ofa second cyclonic dehumidifying comminuter to further dry saidcomminuted and dehydrated sewage sludge into a powdery consistency.
 7. Amethod of processing municipal sludge, comprising the steps of: feedingsaid municipal sludge into an air flow of a first cyclonic dehumidifyingcomminuter to comminute said municipal sludge and to effect dehydrationthereof, the comminuted and dehydrated municipal sludge being dischargedat a first moisture content through a material discharge opening at abottom portion of said cyclonic comminuter while moisture laden air flowis discharged through an air discharge opening, the rate at which saidmunicipal sludge is fed into said cyclonic comminuter being a functionof the actual moisture content of said comminuted and dehydratedmunicipal sludge discharged through said material discharge openingcompared to a desired moisture content; monitoring the actual moisturecontent of said comminuted and dehydrated municipal sludge dischargedthrough said material discharge opening; sterilizing said discharged airflow after being exhausted from said comminuter to remove pathogenstherefrom before being released to the atmosphere; passing saidcomminuted and dehydrated municipal sludge through a sterilizationdevice after being discharged from said cyclonic comminuter to destroypathogens therein; and further processing said sterilized municipalsludge for shipment to a remote location.
 8. The method of claim 7wherein said further processing step comprises the step of: passing saidcomminuted and dehydrated municipal sludge into a second cyclonicdehumidifying comminuter to produce a further dehydrated municipalsludge having a moisture content of approximately 10%.
 9. The method ofclaim 7 wherein said feeding step is controlled to produce a moisturecontent of said comminuted and dehydrated municipal sludge beingdischarged from said material discharge opening in the range of 25% to35%.
 10. The method of claim 7 wherein said feeding step includes thestep of: conveying said municipal sludge into an infeed opening in saidcyclonic comminuter by an auger that will meter the flow of saidmunicipal sludge at a desired flow rate.
 11. The method of claim 10wherein said auger mixes municipal sludges from at least two differentsupply sources containing different levels of moisture before meteringthe mixed municipal sludge into said infeed opening.
 12. A method ofprocessing municipal sludge waste, comprising the steps of: feeding saidmunicipal sludge waste into an air flow of a first cyclonicdehumidifying comminuter to comminute said sewage sludge and to effectdehydration thereof, comminuted and dehydrated municipal sludge wastebeing discharged through a material discharge opening at a bottomportion of said cyclonic dehumidifying comminuter while moisture ladenair flow is discharged through an air discharge opening; monitoring theactual moisture content of said comminuted and dehydrated municipalsludge waste discharged through said material discharge opening;controlling the rate at which said municipal sludge waste is fed intosaid cyclonic comminuter being a function of the actual moisture contentof said comminuted and dehydrated municipal sludge waste dischargedthrough said material discharge opening compared to a desired moisturecontent; sterilizing said discharged air flow after being exhausted fromsaid comminuter to remove pathogens therefrom before being released tothe atmosphere; and passing said comminuted and dehydrated municipalsludge waste through a sterilization apparatus after being dischargedfrom said cyclonic comminuter to destroy pathogens therein and create asterilized municipal sludge waste.
 13. The method of claim 12 furthercomprising the step of: further processing said sterilized municipalsludge waste for shipment to a remote location.
 14. The method of claim13 wherein said desired moisture content of said comminuted anddehydrated municipal sludge waste discharged from said first cyclonicdehumidifying comminuter is in the range of 25% to 35%.
 15. The methodof claim 14 wherein said step of further processing said sterilizedmunicipal sludge waste includes the step of: pelletizing said sterilizedmunicipal sludge waste.
 16. The method of claim 14 wherein said step offurther processing said sterilized municipal sludge waste includes thestep of: feeding said sterilized municipal sludge waste into a secondcyclonic dehumidifying comminuter to further dry said sterilizedmunicipal sludge waste into a powdery consistency.
 17. The method ofclaim 16 wherein said step of feeding said sterilized municipal sludgewaste into a second cyclonic dehumidifying comminuter produces a furtherdehydrated municipal sludge waste having a moisture content ofapproximately 10%.
 18. The method of claim 14 further comprising thestep of: using an auger to convey said sewage sludge to an infeedopening in said cyclonic comminuter, said auger mixing municipal sludgewaste containing different levels of moisture before metering the mixedmunicipal sludge waste into said infeed opening.